Exhaust brake modulating control system

Abstract

An exhaust brake modulating control system is provided for an internal combustion engine having a turbo-charger and source of pressurized fluid. The system includes a double-acting piston-cylinder assembly having one cylinder end communicating with the engine exhaust manifold and an opposite end separated from the one end by a piston head. An adjustable control valve is provided having an outlet connected to the cylinder second end, and a plurality of inlets selectively connected to the outlet. One inlet communicates with the pressurized fluid source and a second inlet is vented to the atmosphere. Communicating with the exhaust manifold is an inlet of a hollow section in which a rotor is rotatably mounted. The hollow section has an outlet separated from the inlet by the rotor. The outlet communicates with the turbine wheel chamber of the turbo-charger. When the rotor assumes a first selected position, substantially unrestricted exhaust gas flow past the rotor occurs. When the rotor assumes a second selected position, gas flow is substantially blocked by the rotor. The rotor and piston head are operatively connected whereby the rotor is responsive to relative movement of the piston head within the cylinder. When the control valve connects the cylinder second end to the pressurized fluid source, the fluid pressure will balance a predetermined gas pressure on the piston head whereby the head will cause the rotor to assume a position that generates a predetermined exhaust braking effect.